Effects of beach roughness and permeability on swash hydrodynamics

New large-scale laboratory experiments were conducted to increase understanding of the key fundamental processes affecting bore-driven swash hydrodynamics. To investigate the effects of roughness, experiments were carried out on impermeable beaches roughened by gluing 1.5mm, 6mm and 10mm sediment to the beach surface. In addition experiments were carried out on permeable but immobile beaches with sediment sizes 1.5mm and 10mm to investigate the effects of permeability. Velocities and depths were measured simultaneously at various locations along the beaches using a combined PIV/LIF technique. The paper presents sample results from the detailed datasets, showing the effects of roughness and permeability on swash lens, shoreline position, velocity profiles and depth-averaged velocities